Bare with me please, I am new to this. I have 2 T105 batteries. Its winter time here in Utah, and I have take the batteries out and I have them hooked to a battery charger at the moment. They are in basement, where its about 70 degrees. My garage would have been 40 degrees. One problem, is the charger only puts out 6Amps, so i know this will take a while. Its a 2/4/6 amp charger. I understand I need to charge them to 14.7V. I am confused about the 14.7 Is that the end voltage after charging or the voltage i need to reach while the charger is attached?. So, if I remove charger, let them rest of 6-12 hours connected to nothing. Should it then read 14.7V or if not, then what voltage should it read? Before I put the charger on this morning, it read 12.77 volts. About 20 min after having it on, it reads 14.4.

I am concerned that I might over-charge these. Also, I noticed a small amount of blackness on the positive terminals. Does this mean I damaged them somehow? These batteries were new last summer.

I am excited for the summer to test these. I bought the morningstar TS-45 near the end of the season. I barely got it hooked up, and a few days later put the cover over my 5th wheel. I have 2, 100W panels on the roof. I think I measured 17V coming into the charge controller.

I plan on getting a specific gravity reader too, I read that it is more accurate. I saw some article on C20 or something. Honestly, it was very confusing to me.

Since you have two, hook them in series and charge them as a 12 volt battery. If you don't combine them then charge each as a 6 volt battery. If there is an amp meter on the charger, then charge until you see the current go down to less than an amp. If your charger is a smart charger, it will take care of dropping the voltage to the float level. If the charger is a dumb one then disconnect when it looks like you have them charged.

Since you have two, hook them in series and charge them as a 12 volt battery.

Correct. Since you brought them inside (I do the same), cable them together in series and think of both batteries as one big 12v battery. Charge them as such. That way they both get charged equally and at the same rate. Make sure electrolyte levels are where they are suppose to be.I do the same with my house batteries for the TT. However, I do leave them in my garage. Ambient temperature. In a MI winter, anything goes. I use a Battery Tender Plus to maintain them during storage. Been doing so for years. With proper electrolyte levels and a float charge to keep them "warm", you will be fine. No issues so far. Link below for charger if interested.

The garage would have been okay since it was above freezing in their...... If you have a automatic charger it should turn its self off automatically in the 2 amp maintenance setting.... Which is the setting you want when storing batterys for the winter.If not you may have overcharge then. Pop the covers and check the water levels. You may need to top them off...... Not the end of the world12.7 volts at standing isent .Bad. How old are they

Bare with me please, I am new to this. I have 2 T105 batteries. Its winter time here in Utah, and I have take the batteries out and I have them hooked to a battery charger at the moment. They are in basement, where its about 70 degrees. My garage would have been 40 degrees. One problem, is the charger only puts out 6Amps, so i know this will take a while. Its a 2/4/6 amp charger. I understand I need to charge them to 14.7V. I am confused about the 14.7 Is that the end voltage after charging or the voltage i need to reach while the charger is attached?. So, if I remove charger, let them rest of 6-12 hours connected to nothing. Should it then read 14.7V or if not, then what voltage should it read? Before I put the charger on this morning, it read 12.77 volts. About 20 min after having it on, it reads 14.4.

I am concerned that I might over-charge these. Also, I noticed a small amount of blackness on the positive terminals. Does this mean I damaged them somehow? These batteries were new last summer.

I am excited for the summer to test these. I bought the morningstar TS-45 near the end of the season. I barely got it hooked up, and a few days later put the cover over my 5th wheel. I have 2, 100W panels on the roof. I think I measured 17V coming into the charge controller.

I plan on getting a specific gravity reader too, I read that it is more accurate. I saw some article on C20 or something. Honestly, it was very confusing to me.

Any guidance on this topic is much appreciated!!

12.7V is the voltage a fully charged battery should read. Charge your battery to a full charge, take the battery off the charger, wait 30 minutes and then test the battery with a digital meter. It should now read 12.7V, if it does not more charging is needed. The key is to wait 30 min and then when you test the "surface charge" should disipate. 14.7 is a charging voltage to get a fully charged battery. It takes as a minimum of 1V more as a minimum charging voltage to overcome the internal resistance of the battery.

Your objective should be to get the pair fully charged (12.6-12.7v at rest) and then keep them that way. The 2A trickle or maintenance setting on your charger should be fine once the batts are fully charged.

The battery monitor will show you exactly how many AH (Amp Hours) were used and replaced so you can always know the state of charge of your battery.

Any lead acid battery which is not brought to 100% at least every 5-7 days will loose capacity. Additionally any lead acid battery which is regularly discharged more than 25% of the total charge will have a shorter life.

The pair of T105's wired in series is rated at about 225AH at 12V. So using more than about 55AH before charging will shorten their life.

The desirable charging voltage depends on the state-of-charge (percentage of full charge). Once the battery reaches near full charge (90-100%), the optimal voltage is in the 13.3-13.6 range. 14.4 or more is suitable only when the battery SOC is low, maybe under 60%. You do not want a continuous 14.4-14.7v charge because it will boil away the electrolyte if it continues once the battery gets near 100% charge.

I had a Schumacher 2/4/6 amp charger but it was not a "Smart" charger and would continue boiling the battery instead of going to float mode as a Battery Minder type would. Using it is fine every 30 days or so but unless it specifically mentions having a maintenance or float mode I would not leave it connected.

here is a couple of very simple to understand common battery charts that you can view and use .

These charts are good, only if you make sure the batteries are at "rest" and not under a load of more than a few amps. Put a, 10% of capacity load, on the battery and the voltage will drop to make it look like the battery is not charged to the levels in the chart.

"Rest" means it as been an hour or two since the battery has had a charge or float voltage applied.

Ok, since you are talking about charging on a bench I have two suggestions.

One, Get the smallest Progressive Dynamics 9200 sereies converter you can lay your hands on, that will be a 9235 or 9245 most likely

2: any small Smart charger, you 2/4/6 amp job is just fine.. Remember, a small charger will take a long time, but you have months so no problem

Now if it's not a smart charger check often.. Let the battery sit for at least 2 hours.. Then measure voltage Use the chart

Treat the two batteries, connected in series, as a Single 12 volt (Size 4D if you want to know the equivalent) by the way.. For installed, that is what they are.. So treat them as such.

Using the chart, and the value of 220 for capacity... estimate the time needed to bring to full at the charger's setting.. NOTE, it will take longer.. But if for example the voltage chart, or better yet a temperature compensated hydrometer, shows say 80%, well that means you have 20% or 44 amp hours to go, so 44/6=7 1/3 hours, so come back in 7 hours and re-test, then you may find 10% left, so come back in 3-4 hours and test and continue till you hit FULL.

Or, when you get over 90% full, switch to a good quality Battery-Minder type prodct, only 1-4 amps, this will top it off, eventually, and keep it there.

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